Marine propulsion system



- March 5, 1963 N. w. LEWIS MARINE PROPULSION SYSTEM Filed cm, 2, 1961 17 Z5 Z5 Z7 INVENTOR. NEILsmvM. L swls United States atent O 3,079,751 IMARINE PRQPULSIGN SYSTERE Neilson W. Lewis, 18 Highiand Ava, Bala-Cynwyd, Pa. Filed fist. 2, 1961, Ser. No. 142,266 1 Claim. (Cl. 6li35.5)

This invention relates generally to propulsion systems for vessels and more specifically to propulsion systems employing the ram jet principle.

It is an object of the present invention to provide a marine propulsion system which operates on the ram jet principle and using steam pressure as the motivating force.

It is another object of the present invention to provide a marine propulsion system wherein it will be possible to develop greater speeds than are presently possible with conventional screw propeller propulsion system presently used in vessels.

It is still another object of the present invention to provide a marine propulsion system which should be partieularly adaptable for use in submarines where power is generally plentiful and speed is at a premium.

It is a still further object of the present invention to provide a marine propulsion system operating on the ram jet principle wherein the device comprises relatively few moving parts, thus assuring long operation without breakdown or repairs and consequently less expensive to produce.

Other objects of the invention are to provide a marine propulsion system bearing the above objects in mind which is of simple construction, has a minimum number of parts, is inexpensive to manufacture and ethcient in operation.

For other objects and for a better understanding of the invention, reference may be had to the following detailed description taken in conjunction with the accompanying drawing, in which:

FIGURE 1 is a side elevational view of a ship shown partly in cross section and showing the present invention incorporated therein;

FIG. 2 is a cross sectional end view taken along the lines 2-2 of FIG. 1 and looking in the direction of the arrows thereof.

Referring now to the drawing in detail, the numeral 10 represents a marine propulsion system according to the present invention wherein there is a longitudinally extending tube 11 having an interior opening 12 as shown in FIG. 1 of the drawing. The tube 11 extends rearwardly from the stem of the vessel, as indicated at 13, being securely fastened thereto and having the interior of the tube 11 communicating with the water 14 of the sea. Thus, the water may enter the forward end or" the tube and be directed rearwardly as will be shown. At some point in the ship between the stem and the stern the tube communicates with a steam chamber 16, the chamber 16 being provided with heating elements 17 which may be of the type carrying hot fluid therethrough or it may be of the type that are known as electrical resistance heaters. The heaters extend through the wall 18 of the steam chamber and communicate with the interior 19 thereof. A one-way valve 29 is provided at the rear of the tube 11 at a point where it communicates with the steam chamber. As shown, the valve 2!? pivots at 21 and can move only in one direction to admit water rearwardly therethrough, but will not permit water passing forwardly thereof. Rearwardly of the steam chamber 16 the tube 111 communicates with a gooseneck construction 22 wherein the segment nearest the steam chamber depends downwardly forming a lower bend 23. Adjacent the lower bend 23 the gooseneck comprises an upwardly extending segment 24; adjacent the upwardly extending segment the gooseneck element has a bend 25 which is located on ahigher level within the vessel than the top of the steam chamber. Adjacent the bend 25 there is a downwardly extending segment 26, while adjacent the downwardly extending segment 26 there is a bend 27 which completes the gooseneck element. Adjacent the bend 27 the tube extends rearwardiy in a horizontal plane as indicated at 23 and communicates with the stern 15 of the ship, being rigidly afiixed thereto, and the interior opening within the tube communicating with the sea.

Thus, means have been provided for permitting the sea water to pass through the vessel from stem to stern. The tube ends may be fastened to the stem and stern by means of welding, riveted plates or any other conventional manner, or by the means whereby sea water will be unable to leak into the vessel.

The operation of the ram jet projulsion system is as follows: At the start of the operation the tube and the steam chamber are filled with water. To get under way, heat is applied by means of the heating elements to the steam chamber, thereby heating the sea water and generating steam, and subsequently building up pressure within the line. This pressure reacts against the check valve and expels a jet of water from the stern end of the tube thereby driving the ship in a forward direction. The steam expands, clearing all water out of the steam chamber and the tube aft of the check valve. The pressure at this point begins to drop, thereby permitting the check valve to open and allowing water from the front of the vessel to enter the tube and into the steam chamber, and then be forced by the gooseneck to rise. Pres sure then builds up again, closing the check valve and the cycle continues. It is understood that two or more such systems could be used within a single vessel, if desired.

It is also understood that this invention is applicable to surface vessels as well as undersea craft.

While various changes may be made in the detail construction, it shall be understood that such changes shall be Within the spirit and scope of the present invention as defined by the appended claim.

What I claim as new and desire to protect by Letters Patent of the United States is:

In a marine propulsion system the combination of an entry duct for conveying sea water, means for heating said sea water adjacent the rear end of said entry duct, 21 gooseneclr element adjacent the rear end of said means for heating said sea water and an egress duct adjacent the rear end of said gooseneck element, said entry duct comprising a tube having a hollow interior, the forward end of said tube being affixed to the stem of a vessel and the said interior of said tube communicating with the open sea Water, and said egress duct comprising a tube, the rear end of which is aflixed to the stern of a vessel and the interior of said tube communicating with the open sea water, said means for heating said sea water comprising a steam chamber having a plurality of heating elements extending within said steam chamber and said steam chamber having a one-way valve adjacent the rear end of the entry tube, said one-way valve permitting water to move rearwardly from said entry tube into said steam chamber and said valve closing upon increase of pressure within said chamber and said gooseneck element comprising a tube, the forward end of which depends downwardly below the level of the entry tube and rearwardly thereof and extending upwardly to a level higher than said steam chamber and rearwardly thereof depending downwardly to communicate with saidegress tube.

References Cited in thefile of this patent UNITED STATES PATENTS FOREIGN PATENTS Great Britain May 19, 1948 

